Rail systems for enclosing property are known to incorporate a wide variety of designs. A particularly advantageous rail system is based on transverse elongated hollow metal rails. In particular the hollow rails preferably comprise rectangular tubes. It is desirable to provide means for attaching the ends of the rails to upright posts. In addition it is desirable to provide means for supporting balusters between upper and lower rails, at spaced intervals between the posts.
Such rail systems may provide an ornamental system but usually will be required to provide some form of physical restraint. Forces are usually lateral forces, and also vertical forces and it is desirable to ensure that such rails are of adequate strength to resist such forces.
In addition to these factors it is desirable, from the view point of aesthetics and appearance that the metallic hollow tubular rails shall abut securely up against the sides of the posts. It will be borne in mind that all of these systems must be adaptable to a wide variety of different types of property and to variations in terrain, and they must be adapted for installation by service personnel in a systematic and repeatable fashion.